Observation of Discrete, Vortex Light Bullets

Eilenberger, Falk; Prater, Karin; Minardi, Stefano; Geiß, Reinhard; Röpke, U.; Kobelke, Jens; Schuster, Kay; Bartelt, Hartmut; Nolte, Stefan; Tünnermann, Andreas; Pertsch, Thomas

doi:10.1103/physrevx.3.041031

Cited by 56 publications

(55 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Consequently, the loss effect on transport [16], which could lead to regimes such as sub/super-diffusive or even super-ballistic ones [17] in addition to the changes on the band structure as a result of higher order couplings [18] are open questions for futher investigations [11]. It is also intersting to study the impact of our results on the two-dimensional array of waveguides as candidates for ultrahigh-capacity optical communications [19] or spatiotemporal vortex soliton (a result of non-linear Kerr effect) [20,21] and their dynamical properties. …”

Section: Arxiv:14085740v2 [Physicsoptics] 12 Sep 2014mentioning

confidence: 99%

Impact of Loss on the Wave Dynamics in Photonic Waveguide Lattices

et al. 2014

View full text Add to dashboard Cite

We analyze the impact of loss in lattices of coupled optical waveguides and find that in such case, the hopping between adjacent waveguides is necessarily complex. This results not only in a transition of the light spreading from ballistic to diffusive, but also in a new kind of diffraction that is caused by loss dispersion. We prove our theoretical results with experimental observations. PACS numbers: PACS numbers: 42.25. Bs, 42.79.Gn, 72.10.Bg, 73.23.Ad Absorption is an intrinsic feature of photonic systems, arising due to the laws of causality [1]. It results in decoherence and, hence, in a considerable change in the dynamics of optical waves. However, it is generally agreed that in the particular case of homogeneous and isotropic loss the impact on the amplitude distribution in the system vanishes, besides a global decay of the integrated power [1]. A very prominent photonic system is arrays of evanescently coupled waveguides [2], where a tailored absorption (or absorption/gain) distribution is the basis for a multitude of unexpected physical phenomena, such as exceptional points [3], unusual beam dynamics [4], spontaneous PT -symmetry breaking [5], non-reciprocal Bloch oscillations [6] and dynamic localization [7], unidirectional cloaking [8], and even tachyonic transport [9]. Owing to the intuition described above, if all lattice sites exhibit exactly the same absorption, its impact vanishes in the evolution equations of these systems. In a more mathematical language, in this case absorption adds to the Hamiltonian as a pure diagonal matrix with identical elements, which can be removed by normalization.In our work we show that absorption in coupled waveguide systems does always impact the light dynamics, even if it is homogeneous and isotropic in all lattice sites. Due to the imaginary part of the dielectric function (that describes the absorption) imaginary off-diagonal elements in the Hamiltonian appear that cannot be removed by normalization, causing significant deviations in the light dynamics compared to the Hermitian case. However, our theory holds for all Schrödinger type systems that can be mapped onto a tight binding lattice, e.g., paraxial waves in optics or mechanics as well as quantum dynamics in spin chains, population transfer in multi-level systems and graphene. Our theory supplements the knowledge about the influence of non-Hermiticity to all these systems in general including the effect of PT symmetry.In order to study the impact of absorption in such systems, we consider a one-dimensional array of N identical single mode optical waveguides with width 2w, inter-site spacing d, and the complex relative electric permittivity + i at the positions x n (n = 1, 2, ..., N ), which is surrounded by a bulk material (with 0 + i 0 ). A sketch of this system is shown in Fig. 1.The dynamics of wave propagating through this system is governed by the Helmholtz wave equationwhere ψ(x, z) is the electric field amplitude, k 0 = ω c is the propagation constant in free space, and ε(x) is relative electric ...

show abstract

Section: Arxiv:14085740v2 [Physicsoptics] 12 Sep 2014mentioning

confidence: 99%

Impact of Loss on the Wave Dynamics in Photonic Waveguide Lattices

et al. 2014

View full text Add to dashboard Cite

show abstract

“…The considered discrete optical vortices also have the potential for high power field trapping and transfer in MCF, which provides a method to manage and control the nonlinearity and to design new type of switches 59 , sources of high brightness coherent radiation or uniform light sources with tailored phase profiles. Moreover, an intriguing extension of this work is to generate and manage spatiotemporal vortex light bullets in MCF settings [46][47][48][49] . …”

Section: Discussionmentioning

confidence: 99%

Stable optical vortices in nonlinear multicore fibers

et al. 2015

View full text Add to dashboard Cite

The multicore fiber (MCF) is a physical system of high practical importance. In addition to standard exploitation, MCFs may support discrete vortices that carry orbital angular momentum suitable for spatial-division multiplexing in high-capacity fiber-optic communication systems. These discrete vortices may also be attractive for high-power laser applications. We present the conditions of existence, stability, and coherent propagation of such optical vortices for two practical MCF designs. Through optimization, we found stable discrete vortices that were capable of transferring high coherent power through the MCF. Keywords: coherent energy propagation; multicore fibers; nonlinear vortices INTRODUCTION Vortex structures are widespread in nature and are found in both macroscopic atmospheric phenomena, such as tornadoes and the Great Red Spot of Jupiter, and microscopic-scale objects in quantum physics. Mathematically, vortices are related to topological defects, the accumulation of geometrical phases, and the phase singularity of a complex linear or nonlinear field (see, e.g., Refs. 1-8 and references therein).Optical vortices present a fascinating and expanding area of research that combines fundamental theoretical and mathematical science and maturing applied technologies (see recent review 4 ). Optical vortices are characterized by a wave field with zero intensity, an undefined phase in the vortex center (pivot point) and the presence of a screw dislocation of the wave front 5,6 . All transmutations of vortices in linear and nonlinear fields obey the conservation of the topological charge S, which is defined as the total change of the phase along a closed curve surrounding the pivotal point of the vortex divided by 2p. The special behavior of the phase and amplitude near the vortex pivot point results in the circular flow of energy in optical vortices [7][8][9][10] . This property is closely related to the ability of optical vortices to carry orbital angular momentum and energy [11][12][13][14] . This property is interesting for various applications, such as in optical traps [15][16][17] , information transmission 18-20 , astrophysics 21,22 , microscopy 23,24 , and laser micromachining 25,26 .In nonlinear media, optical vortices are treated as (topological) vortex solitons 4,27,28 . Such topologically stable pulses can act as information carriers 4,[29][30][31] . It is important that continuum vortex solitons are highly sensitive to azimuthal instability. Stabilization is possible by applying optically induced photonic lattices, which lead to a discrete optical vortex field. Different types of discrete lattice vortex solitons were theoretically predicted in the Refs. 32-35 and experimentally demonstrated in the Refs. 36,37. Discrete vortex solitons can also be created in photonic crystal fibers and other types of photonic lattices 38,39 . Discrete vortex solitons are frequently associated with soliton clusters, which feature interesting mobility properties and

show abstract

“…Characteristic examples are various methods elaborated for the stabilization of three-dimensional spatiotemporal solitons ("light bullets" [59]), which are subject to strong instabilities in both two-and three-dimensional uniform media [60][61][62]. It was demonstrated experimentally that both fundamental spatiotemporal solitons [63] and ones with embedded vorticity [64] can be made stable (in fact, as semi-discrete solitons) in the above-mentioned systems created as bundles of parallel waveguiding cores in bulk silica samples [26]. In fact, the commonly known stability of temporal optical solitons in nonlinear fibers [47] is also an example of the stabilization of a localized mode which is-strictly speaking-a three-dimensional one, with the self-trapping in the temporal (longitudinal) direction induced by the nonlinearity, while the transverse trapping is secured by the fiber's guiding properties, which are not essentially affected by the nonlinearity.…”

Section: Nonlinear Waveguidesmentioning

confidence: 99%

Editorial: Guided-Wave Optics

Malomed

2017

Applied Sciences

View full text Add to dashboard Cite

Guided waves represent a vast class of phenomena in which the propagation of collective excitations in various media is steered in required directions by fixed (or, sometimes, reconfigurable) conduits. Arguably, the most well-known and practically important waveguides are single-mode and multi-mode optical fibers [1,2], including their more sophisticated version in the form of photonic crystal fibers [3] and hollow metallic structures transmitting microwave radiation [4]. Light pipes, in the form of hollow tubes with reflecting inner surfaces, are used in illumination techniques. On the other hand, medical stethoscopes offer a commonly known example of a practically important acoustic waveguide. New directions of studies in photonics are focused on waveguides for plasmonic waves on metallic surfaces [5][6][7] (which provide the possibility of using wavelengths much smaller than those corresponding to the traditional optical range, and thus offer opportunities to build much more compact photonic devices) and on the other hand, on the guided transmission of terahertz waves, which also have a great potential for applications [8].Outside of the realm of photonics (optics and plasmonics) and acoustics, wave propagation plays a profoundly important role in many other areas; accordingly, waveguiding settings have drawn a great deal of interest in those areas as well. In particular, as concerns hydrodynamics, natural waveguides-which may be very long-exist for internal waves propagating in stratified liquids (e.g., in the ocean) [9]. Various settings in the form of waveguides for matter waves are well known in studies of Bose-Einstein condensates in ultracold bosonic gases [10,11]. In solid-state physics, guided propagation regimes for magnon waves in ferromagnetic media are a subject of theoretical and experimental studies [12]. In superconductivity, long Josephson junctions are waveguides for plasma waves [8,13]. The significance of waveguiding in plasma physics is also well-known; e.g., Ref [14][15][16].Below, a very brief overview of basic theoretical models and experimental realizations of various physical implementations of the waveguiding phenomenology is given. The text is structured according to the character of the guided wave propagation: linear or nonlinear and conservative or dissipative, as well as according to the materials used in the underlying settings, natural or artificial.This presentation definitely does not aim to include an exhaustive bibliography on this vast research area. References are given chiefly to review articles and books summarizing the known results, rather than to original papers where the results were first published. However, in some cases original papers are also cited if it is necessary in the context of the presentation. Linear WaveguidesThe basic waveguiding structure is a single-mode conduit, designed with a sufficiently small transverse size and boundary conditions at the boundary between the guiding core and surrounding cladding, which admits the propagation of a single tr...

show abstract

Observation of Discrete, Vortex Light Bullets

Cited by 56 publications

References 49 publications

Impact of Loss on the Wave Dynamics in Photonic Waveguide Lattices

Impact of Loss on the Wave Dynamics in Photonic Waveguide Lattices

Stable optical vortices in nonlinear multicore fibers

Editorial: Guided-Wave Optics

Contact Info

Product

Resources

About